US4517502A - Load monitoring circuit for electric motors - Google Patents

Load monitoring circuit for electric motors Download PDF

Info

Publication number
US4517502A
US4517502A US06/594,773 US59477384A US4517502A US 4517502 A US4517502 A US 4517502A US 59477384 A US59477384 A US 59477384A US 4517502 A US4517502 A US 4517502A
Authority
US
United States
Prior art keywords
motor
reference voltage
electric motor
monitoring circuit
transistor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US06/594,773
Other languages
English (en)
Inventor
Hans-Joachim Aschoff
Lothar Cholewa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Vorwerk and Co Interholding GmbH
Original Assignee
Vorwerk and Co Interholding GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Vorwerk and Co Interholding GmbH filed Critical Vorwerk and Co Interholding GmbH
Assigned to VORWERK & CO. INTERHOLDING GMBH reassignment VORWERK & CO. INTERHOLDING GMBH ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: ASCHOFF, HANS-JOACHIM, CHOLEWA, LOTHAR
Application granted granted Critical
Publication of US4517502A publication Critical patent/US4517502A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
    • A47L9/00—Details or accessories of suction cleaners, e.g. mechanical means for controlling the suction or for effecting pulsating action; Storing devices specially adapted to suction cleaners or parts thereof; Carrying-vehicles specially adapted for suction cleaners
    • A47L9/28—Installation of the electric equipment, e.g. adaptation or attachment to the suction cleaner; Controlling suction cleaners by electric means
    • A47L9/2889—Safety or protection devices or systems, e.g. for prevention of motor over-heating or for protection of the user
    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
    • A47L9/00—Details or accessories of suction cleaners, e.g. mechanical means for controlling the suction or for effecting pulsating action; Storing devices specially adapted to suction cleaners or parts thereof; Carrying-vehicles specially adapted for suction cleaners
    • A47L9/28—Installation of the electric equipment, e.g. adaptation or attachment to the suction cleaner; Controlling suction cleaners by electric means
    • A47L9/2805—Parameters or conditions being sensed
    • A47L9/2831—Motor parameters, e.g. motor load or speed
    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
    • A47L9/00—Details or accessories of suction cleaners, e.g. mechanical means for controlling the suction or for effecting pulsating action; Storing devices specially adapted to suction cleaners or parts thereof; Carrying-vehicles specially adapted for suction cleaners
    • A47L9/28—Installation of the electric equipment, e.g. adaptation or attachment to the suction cleaner; Controlling suction cleaners by electric means
    • A47L9/2836—Installation of the electric equipment, e.g. adaptation or attachment to the suction cleaner; Controlling suction cleaners by electric means characterised by the parts which are controlled
    • A47L9/2842—Suction motors or blowers
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/08—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric motors
    • H02H7/085—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric motors against excessive load
    • H02H7/0855—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric motors against excessive load avoiding response to transient overloads, e.g. during starting

Definitions

  • the present invention relates to a monioring circuit for supervising different operational conditions of an electric motor and in particular it relates to a monitoring circuit of the type which employs a measuring resistance connected in series with the stator winding of the electric motor to produce a voltage drop which is proportional to the electric currrent flowing through the motor.
  • Monitoring circuits of this kind are known and find practical use for example in a vacuum cleaner so as to monitor load of the driving electric motor and disconnect the same when an overload occurs.
  • the electric motor is controlled via a thyristor and the measuring resistance is connected in the thyristor circuit to provide a voltage which is proportional to the motor current.
  • This actual value voltage is applied via a timing RC member to a voltage dividing potentiometer which in turn is connected to the base of a transistor.
  • This transistor is connected parallel to the thyristor circuit.
  • the voltage dividing potentiometer adjusts the actual value voltage to such a value that during normal operational conditions of the motor the transistor is not yet switched on.
  • the aforementioned RC member prevents the first transistor from immediately disconnecting the electric motor.
  • the setting of the nominal value by the voltage dividing potentiometer is extremely critical inasmuch as the RC member simultaneously generates during the start of the motor a certain voltage across the voltage dividing potentiometer. Accordingly, the desired threshold value cannot be adjusted to any arbitrary magnitude because in the case of low threshold values reached during the starting operation are in the order of the voltage across the RC member, the transistor is switched on and restarts the motor. Therefore, the magnitude of the adjusted threshold value must be sufficiently large to be above the voltage value across the RC member. This limitation in prior art monitoring circuits is considerable disadvantageous.
  • a further object of this invention is to provide such an improved monitoring circuit which is relatively simple and can be produced at low cost.
  • a load monitoring circuit for electric motors in a combination which comprises a measuring resistor connected in series with the stator winding of the motor to produce an actual load value signal, an adjustable reference voltage source, a comparison circuit having one input coupled to the measuring resistance, a second input coupled to the variable reference voltage source and an output and means for automatically adjusting from zero to a maximum value the adjustable source of reference voltage to at least three main operational conditions of the electric motor, namely to a starting load operational condition, a normal load operational condition, and a overload operational condition.
  • the comparison circuit is in the form of an operational amplifier whose inverting input is connected to an adjustable voltage divider controlled by a switching transistor whose base is coupled to a RC circuit which delays the switching on of the transistor during the starting phase of the motor, thus setting a maximum reference or nominal value which cannot be tresspassed by the actual load value during the starting phase.
  • the transistor is automatically switched on and produces at the inverting input of the operational amplifier a reference value corresponding to the normal operational load.
  • a signal derived from the output of the operational amplifier is fed back to the voltage source to adjust the same to a zero reference voltage and to retain this condition.
  • a stop signal is fed back to the control circuit for the driving motor so that the latter is stopped. It can be restarted only after disconnection from the main power supply.
  • the invention has the substantial advantage residing in the fact that the reference or threshold value for disconnecting the motor can be adjusted without regard to the voltage which is developed across the timing RC member actuated during the starting phase of the electric motor, and at the same time, any manual adjustment of the reference threshold value for the starting operation can be dispensed with.
  • the single FIGURE illustrates a circuit diagram of an exemplary embodiment of a motor load monitoring circuit according to this invention.
  • An eletric motor M to be monitored has its stator windings connected to terminals N 1 and N 2 of a supply line via a control triac TC whose gate is controlled by a diac DC and a series connected measuring resistor R 5. Accordingly, voltage drop across the resistor R 5 is proportional to momentary current flowing through the electric motor.
  • This voltage drop which is the measure of the actual motor load is rectified in a diode D 2 and integrated in an integrating circuit R 6, C 3.
  • Voltage across the integrating capacitor C 3 indicates the actual value of the momentary current and this actual value signal is applied via a decoupling diode D 3 and a series connected resistor R 13 to a noninverting input N of an operational amplifier OP which is connected as a voltage comparison circuit.
  • Nominal reference voltage values generated in an adjustable reference voltage source which will be described in greater detail below, are applied to the inverting (minus) input of the amplifier OP.
  • the nominal reference voltage value according to one feature of this invention, successively and automatically is adjusted to different magnitudes which correspond to the momentary operational condition of the electric motor.
  • the first or starting nominal reference value is derived from the motor supply voltage stabilized by a Zener diode D 5. This stabilized supply voltage is applied to a voltage divider consisting of resistors R 16 and potentiometer P 1 which is connected to the inverting input I of the operational amplifier OP. The potentiometer P 1 is further connected in series with the collector-emitter path of a switching transistor T 3. The base B 3 of the latter transistor is connected to a timing RC member consisting of resistor R 10, R 11 and capacitor C 5.
  • the timing member is dimensioned such that after the switching on the power supply, a negative potential on the base B 3 of transistor T 3 rises slowly depending on the time constant of the RC member. As a consequence, at the moment of turning on the power the transistor T 3 is not conductive and the entire supply voltage is applied to the inverting input I of the operational amplifier OP.
  • the supply voltage represents a maximum nominal reference value which cannot be exceeded by the detected actual load value. Accordingly, a momentary increase of the motor current during the starting phase does not produce any disconnection by the comparison circuit.
  • the transistor T 3 switches on and a second nominal reference value adjusted by the voltage divider R 16 and P1 is applied to the inverting input I of the comparator. In this fashion the maximum reference voltage value for starting operational phase of the motor is automatically changed to a second nominal reference value corresponding to normal operation of the motor.
  • the comparison circuit operates with a referenc voltage set for the normal operation of the motor and the monitoring circuit safeguards the motor M against overload.
  • a negative potential is produced at the output A of the operational amplifier OP.
  • the negative output voltage is applied via resistor R 15 to the base terminal B 1 of transistor T 1 which lowers the firing pulses of a diac DC to such an extent that the latter does no longer trigger the triac TC arranged in the control circuit of the electric motor M.
  • the triac TC becomes blocked and interrupts the power supply to the electric motor M and stops the latter.
  • the negative signal from the output A of the operational amplifier OP is applied via resistor R 17 to the base terminal B 4 of a transistor T 4 so that the latter is switched on. Due to the switchover of transistor T 4, the nominal reference voltage at the comparison circuit is brought to zero. As a result, the entire monitoring circuit is brought in a self-retaining condition inasmuch as zero reference voltage does not permit any start.
  • the transistor T 2 is switched on by the output signal from the operational amplifier applied to its base terminal B 2 and discharges the timing capacitor C 5 so that the RC member be ready for restarting operation.
  • the beforementioned decoupling diode D 3 prevents the nominal value signals from reaching via impedances of inputs N and I of the operational amplifier the integrating capacitor C 3 and thus prevents any interference with the generation of the actual value signal.
  • the nominal value range for the load monitoring circuit of this invention is adjustable from zero to a maximum value given by the supply voltage and particular nominal reference voltages corresponding to different operational conditions of the electric motor are automatically adjusted in the manner resembling a preset program so as to reliably supervise the load of the motor and disconnect the same in the case of an overload.
US06/594,773 1983-03-31 1984-03-26 Load monitoring circuit for electric motors Expired - Lifetime US4517502A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19833311771 DE3311771A1 (de) 1983-03-31 1983-03-31 Ueberwachungsschaltung fuer elektromotoren
DE3311771 1983-03-31

Publications (1)

Publication Number Publication Date
US4517502A true US4517502A (en) 1985-05-14

Family

ID=6195213

Family Applications (1)

Application Number Title Priority Date Filing Date
US06/594,773 Expired - Lifetime US4517502A (en) 1983-03-31 1984-03-26 Load monitoring circuit for electric motors

Country Status (6)

Country Link
US (1) US4517502A (pt)
EP (1) EP0123728A1 (pt)
JP (2) JPS59185190A (pt)
AU (1) AU2634884A (pt)
DE (1) DE3311771A1 (pt)
ES (1) ES531168A0 (pt)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4663537A (en) * 1984-07-03 1987-05-05 Keiper Recaro Gmbh & Co. Protective circuit
US4748389A (en) * 1985-02-18 1988-05-31 Matsushita Electric Industrial Co., Ltd. Motor speed control apparatus
US4806832A (en) * 1982-11-23 1989-02-21 Papst Motoren Kg Fan with temperature controlled rotation speed
US5294872A (en) * 1986-10-08 1994-03-15 Hitachi, Ltd. Method and apparatus for operating vacuum cleaner
US5543694A (en) * 1994-01-03 1996-08-06 Eti Systems Control circuit for feedback, motor-operated valve
US5814955A (en) * 1997-03-14 1998-09-29 Eaton Corporation Motor control circuit with a low voltage monitor
US5878523A (en) * 1997-10-30 1999-03-09 Wenzel; Stephen R. Motorized reeling assembly with automatic cut-off
US20050055795A1 (en) * 2003-07-25 2005-03-17 Zeiler Jeffrey M. Air flow-producing device, such as a vacuum cleaner or a blower
US20080272725A1 (en) * 2005-10-07 2008-11-06 Emotron Ab Load Monitor
US20090116160A1 (en) * 2005-09-14 2009-05-07 Cheng-Hsuan Fan Arrangement and method for an integrated protection for a power system
US10130216B2 (en) 2012-08-16 2018-11-20 Vorwerk & Co. Interholding Gmbh Electrically operated kitchen appliance
CN111146767A (zh) * 2019-12-18 2020-05-12 陈鑫 一种多功率电机

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3519472A1 (de) * 1984-07-03 1986-01-16 Keiper Recaro GmbH & Co, 5630 Remscheid Schutzschaltung
EP0247996A3 (de) * 1986-05-27 1989-01-25 AUSTRIA Antriebstechnik G. Bauknecht Aktiengesellschaft Drehstrommotor mit Überhitzungsschutzeinrichtung
DE3634731A1 (de) * 1986-10-11 1988-04-21 Horst W M Kramer Verfahren zur begrenzung oder unterbrechung des stromes einer antriebsvorrichtung beim erreichen oder ueberschreiten eines oberen stromgrenzwertes und schutzschaltung zur durchfuehrung des verfahrens
DE3819166A1 (de) * 1988-06-04 1989-12-07 Marquardt Gmbh Schaltanordnung zur drehzahlsteuerung eines reihenschlussmotors mit drehmomentabschaltung
DE3914312A1 (de) * 1989-04-29 1990-10-31 Telefunken Electronic Gmbh Schaltung zum erkennen der ueberbelastung eines motors
DE4115295A1 (de) * 1991-05-10 1992-11-12 Telefunken Electronic Gmbh Schaltungsanordnung zur steuerung und ueberwachung eines laststromes
US5757596A (en) * 1997-01-21 1998-05-26 Ford Global Technologies, Inc. Motor control assembly and method of controlling same
ES2179388T3 (es) * 1997-01-21 2003-01-16 Vorwerk Co Interholding Aspirador de polvo accionado por medio de un motor electrico, especialmente sistema aspirador de polvo.

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3373330A (en) * 1964-10-15 1968-03-12 Donald F. O'brien Power regulator
US3445725A (en) * 1967-02-02 1969-05-20 Whirlpool Co Solid state lock-out circuit for compressor
JPS5222715A (en) * 1975-08-14 1977-02-21 Matsushita Electric Ind Co Ltd Protection device for motor and control semiconductor element
US4103317A (en) * 1976-06-07 1978-07-25 Val Tech Inc. Motor protector providing phase failure and overload cutoff for three-phase variable voltage variable frequency motor
SU656169A1 (ru) * 1976-09-14 1979-04-05 Mitelman Mikhail V Устройство дл регулировани тока кор электродвигател
JPS54161042A (en) * 1978-06-08 1979-12-20 Toshiba Corp Motor protection system
US4195254A (en) * 1977-08-03 1980-03-25 Caterpillar Tractor Co. Control circuit for a D.C. motor
US4220900A (en) * 1978-06-16 1980-09-02 Sky-Top Sunroofs Ltd. Motor control system for a linearly reciprocating load device such as automotive vehicle closure including sun roof
GB2067370A (en) * 1979-12-28 1981-07-22 Myson Group Ltd Electric motor start up control
US4288828A (en) * 1980-01-17 1981-09-08 Eaton Corporation Protection system for electric motors

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2736009A (en) * 1956-02-21 Lilzlj
US422900A (en) * 1890-03-11 Bridle-bit
US3633073A (en) * 1969-12-05 1972-01-04 Borg Warner Overload and overcurrent regulation and protection system
DE2431540C2 (de) * 1974-07-01 1984-09-13 Brown, Boveri & Cie Ag, 6800 Mannheim Schaltungsanordnung zum Schutz einer elektrischen Maschine gegen zu hohe Erwärmung mit einer Simulationseinrichtung
JPS53132746A (en) * 1977-04-22 1978-11-18 Ricoh Co Ltd Overcurrent protection circuit for reversible motor drive
JPS5678380A (en) * 1979-11-26 1981-06-27 Shibaura Eng Works Co Ltd Motor-driven clamping device

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3373330A (en) * 1964-10-15 1968-03-12 Donald F. O'brien Power regulator
US3445725A (en) * 1967-02-02 1969-05-20 Whirlpool Co Solid state lock-out circuit for compressor
JPS5222715A (en) * 1975-08-14 1977-02-21 Matsushita Electric Ind Co Ltd Protection device for motor and control semiconductor element
US4103317A (en) * 1976-06-07 1978-07-25 Val Tech Inc. Motor protector providing phase failure and overload cutoff for three-phase variable voltage variable frequency motor
SU656169A1 (ru) * 1976-09-14 1979-04-05 Mitelman Mikhail V Устройство дл регулировани тока кор электродвигател
US4195254A (en) * 1977-08-03 1980-03-25 Caterpillar Tractor Co. Control circuit for a D.C. motor
JPS54161042A (en) * 1978-06-08 1979-12-20 Toshiba Corp Motor protection system
US4220900A (en) * 1978-06-16 1980-09-02 Sky-Top Sunroofs Ltd. Motor control system for a linearly reciprocating load device such as automotive vehicle closure including sun roof
GB2067370A (en) * 1979-12-28 1981-07-22 Myson Group Ltd Electric motor start up control
US4288828A (en) * 1980-01-17 1981-09-08 Eaton Corporation Protection system for electric motors

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Conference paper, 1977 Electrical & Electronics Engrs. Tenth Convention, Tel Aviv, Israel (Oct. 10 13, 1977), pp. 97 99. *
Conference paper, 1977 Electrical & Electronics Engrs. Tenth Convention, Tel Aviv, Israel (Oct. 10-13, 1977), pp. 97-99.

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4806832A (en) * 1982-11-23 1989-02-21 Papst Motoren Kg Fan with temperature controlled rotation speed
US4663537A (en) * 1984-07-03 1987-05-05 Keiper Recaro Gmbh & Co. Protective circuit
US4748389A (en) * 1985-02-18 1988-05-31 Matsushita Electric Industrial Co., Ltd. Motor speed control apparatus
US5294872A (en) * 1986-10-08 1994-03-15 Hitachi, Ltd. Method and apparatus for operating vacuum cleaner
US5543694A (en) * 1994-01-03 1996-08-06 Eti Systems Control circuit for feedback, motor-operated valve
US5814955A (en) * 1997-03-14 1998-09-29 Eaton Corporation Motor control circuit with a low voltage monitor
US5878523A (en) * 1997-10-30 1999-03-09 Wenzel; Stephen R. Motorized reeling assembly with automatic cut-off
US20050055795A1 (en) * 2003-07-25 2005-03-17 Zeiler Jeffrey M. Air flow-producing device, such as a vacuum cleaner or a blower
US7712182B2 (en) 2003-07-25 2010-05-11 Milwaukee Electric Tool Corporation Air flow-producing device, such as a vacuum cleaner or a blower
US20090116160A1 (en) * 2005-09-14 2009-05-07 Cheng-Hsuan Fan Arrangement and method for an integrated protection for a power system
US7907377B2 (en) * 2005-09-14 2011-03-15 Richtek Technology Corp. Arrangement and method for an integrated protection for a power system
US20080272725A1 (en) * 2005-10-07 2008-11-06 Emotron Ab Load Monitor
US10130216B2 (en) 2012-08-16 2018-11-20 Vorwerk & Co. Interholding Gmbh Electrically operated kitchen appliance
CN111146767A (zh) * 2019-12-18 2020-05-12 陈鑫 一种多功率电机
CN111146767B (zh) * 2019-12-18 2022-04-26 陈鑫 一种多功率电机

Also Published As

Publication number Publication date
JPH0677497U (ja) 1994-10-28
EP0123728A1 (de) 1984-11-07
DE3311771C2 (pt) 1991-04-18
ES8501927A1 (es) 1984-12-01
ES531168A0 (es) 1984-12-01
AU2634884A (en) 1984-10-04
JPS59185190A (ja) 1984-10-20
DE3311771A1 (de) 1984-10-04

Similar Documents

Publication Publication Date Title
US4517502A (en) Load monitoring circuit for electric motors
US4366426A (en) Starting circuit for single phase electric motors
EP0106539B1 (en) Voltage regulating system for an electrical generator
US3868554A (en) Current limit system for DC motor control
US3761792A (en) Switching circuit for motor start winding
EP1240709B1 (en) Time rate of change motor start circuit
US4375613A (en) Electrical control circuit
US4562389A (en) Automatic screwdriver or torquing tool control system
US3177418A (en) Armature current limiting speed control systems for electric motors
US5589753A (en) Rate effect motor start circuit
US4399394A (en) Electronic motor start switch
US5323287A (en) Protective device for electric motors
EP0373694A1 (en) Diagnostic circuit for units providing current control and protection against excessive heat dissipation for semiconductor power devices
US4496895A (en) Universal single phase motor starting control apparatus
US3452263A (en) Step motor drive system including current feedback
US3403315A (en) Condition responsive control circuit connected to gate a triggered switch
US4204128A (en) Adjustable time delay relay
US5646497A (en) Switching arrangement for controlling the rpm of electric motors
JPS6226277B2 (pt)
US5455469A (en) Comparator controlled delay-on-break devices
US4195324A (en) Heating circuit for an electric motor
US4639657A (en) Electrical control apparatus and methods
US5220258A (en) Drive circuit for a brushless direct-current motor
US5936446A (en) PWM variable voltage load driver with peak voltage limitation
US4016459A (en) Protective system for intermittently operating semiconductor switch

Legal Events

Date Code Title Description
AS Assignment

Owner name: VORWERK & CO. INTERHOLDING GMBH, MUEHLENWEG 17-37,

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:ASCHOFF, HANS-JOACHIM;CHOLEWA, LOTHAR;REEL/FRAME:004289/0392

Effective date: 19840405

Owner name: VORWERK & CO. INTERHOLDING GMBH,GERMANY

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:ASCHOFF, HANS-JOACHIM;CHOLEWA, LOTHAR;REEL/FRAME:004289/0392

Effective date: 19840405

STCF Information on status: patent grant

Free format text: PATENTED CASE

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

FPAY Fee payment

Year of fee payment: 12